| 摘要 |
PROBLEM TO BE SOLVED: To attain a structure that can sufficiently bear a load even in any load area in a case of changing the load of a shell-shaped needle bearing, and can prevent loss torque based on the rotation resistance of a bearing part from uselessly increasing.SOLUTION: The radial gap of a first bearing part 18 is properly made smaller than the radial gap of a second bearing part 19. Consequently, in a state where a load is relatively small, the load is borne only with the first bearing part 18, and in a state where a load is relatively large, the load is borne with the first and second bearing parts 18, 19. |
